1. Field of the Invention
The present invention relates to an electronic component, such as a laminated ceramic capacitor, for example, and in particular, an electronic component including a plurality of internal electrodes that are connected to different potentials within a ceramic sintered body and that are laminated through a ceramic layer.
2. Description of the Related Art
In the past, electronic components have been widely used which include a plurality of internal electrodes that are disposed within a ceramic sintered body. In Japanese Unexamined Patent Application Publication No. 2001-210545, a laminated ceramic capacitor 101 illustrated in FIG. 23A is disclosed. The laminated ceramic capacitor 101 includes a ceramic sintered body 102. Within the ceramic sintered body 102, a plurality of first internal electrodes 103 and a plurality of second internal electrodes 104 are provided.
A first external electrode 105 is provided on a first end surface 102a of the ceramic sintered body 102. A second external electrode 106 is provided on a second end surface 102b. The first external electrode 105 includes a thick-film electrode layer 105a formed by firing conductive paste. Plated films 105b and 105c are laminated on the thick-film electrode layer 105a. The plated film 105b includes Ni and is provided so as to prevent solder leaching. The plated film 105c includes Sn, for example, and is provided so as to improve solderability.
The first and second external electrodes 105 and 106 are arranged so as to cover the first and second end surfaces 102a and 102b of the ceramic sintered body 102. In addition, in order to improve mountability, the external electrodes 105 and 106 include turnback portions extending to a top surface 102c and a bottom surface 102d of the ceramic sintered body 102.
The plated film 105b is formed so as to cover the entire surface of the thick-film electrode layer 105a. The plated film 105c is formed so as to cover the entire surface of the outer surface of the plated film 105b. 
At the time of the formation of the thick-film electrode layer 105a, conductive paste is applied to and fired onto the laminated ceramic capacitor 101. After this firing, a residual stress occurs at a position indicated by an arrow A in FIG. 23B, namely, the end portion of the turnback portion. The residual stress is due to a difference between the thermal expansion coefficients of ceramics and the thick-film electrode layer 105a at the time of firing.
In addition, when the laminated ceramic capacitor 101 is mounted on a substrate, the first and second external electrodes 105 and 106 are bonded to electrode lands on the substrate using conductive bonding material, such as solder or other suitable bonding material. When a stress, such as deflection, is applied from the outside after bonding, a stress occurs at the end portions of the turnback portions of the external electrodes 105 and 106. Namely, a stress occurs at the portion indicated by the arrow A.
As described above, a residual stress at the time of the formation of the external electrode and a stress due to the deflection of the substrate at the time of mounting and after mounting and a stress, such as a thermal shock, are concentrated into the portion indicated by the arrow A. As a result, a problem is caused in that a crack occurs in the ceramic sintered body 102, starting from the portion into which the stresses are concentrated.